The B+W 39mm UV/IR Cut 486M MRC Filter is an interference filter designed to reflect and break up wavelengths on both sides of the visible spectrum (infrared and ultraviolet) in order to gain a more pure transmittance of the visible spectrum. The filter is completely colorless and is comprised of thin layers with varying thicknesses, similar to a multi-coating. By utilizing this method of construction, unwanted UV and IR radiation is not absorbed but rather repeatedly reflected in order to affect and skew the wavelengths in order to provide a steep cutoff between spectrums.
This filter is mainly used with digital and video cameras with a CCD sensor without an internal IR protection filter. A CCD sensor is especially prone to infrared radiation that can result in color shifts and un-sharpness. These effects are due to chromatic aberrations from lenses which are only corrected for visible light that offer no protection to non-visible wavelengths. In the visible range, the transmission curve is very high and straight for a clear, abrupt separation between the visible and non-visible ranges of the spectrum. Since it is optically clear, there is no need for exposure compensation.
The Multi-Resistant Coating (MRC) is both an anti-reflection coating as well as a protective surface. It helps to increase light transmission by reducing reflections, scattered light, and ghosting. Additionally, it offers greater protection to the filter substrate and stays cleaner for longer than uncoated filters.
B+W filters are constructed from high quality Schott glass for increased optical clarity and color fidelity. They feature a brass filter ring for durability as well as jamming prevention. Due to its construction and coating structure, this filter is not suitable for wide-angle lenses with an angle of view greater than 60°.
- Interference filter reflects and breaks up wavelengths on both sides of the visible spectrum.
- By reflecting the UV and IR spectrums, a more pure transmittance of the visible spectrum is possible.
- Designed mainly for use with CCD sensors as they are more susceptible to infrared radiation, which can cause un-sharpness and color shifts.
- Optically clear filter requires no exposure compensation.
- Multi-Resistant Coating offers both protection to the glass and helps to improve light transmission and image quality.
- Constructed from high quality Schott glass for optical clarity.
- Brass filter ring helps to prevent jamming and provides additional strength.